Metallic-filament incandescent electric lamp.



E. GEISEL.

METALLIC FILAMENT INCANDESCENT ELECTRIC LAMP.

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EMIL GEISEL, 01E

' COM]? IBABIIES, LONDON, ENGLAND, ASSIGN'OR T GENERAL ELECTRIC A CORPORATION OF NEW YORK.

METALLIC-FILAMENT INCANDESCENT ELECTRId LAMP.

SpecifleatiersPatent. t t 24,, new,

Application filed October 3, 1912. Serial No. 723,674.

To all whom it may concern:

Be it known that I, Eran. GnIsnL, a subject of the Emperor of Germany, res1ding at Barnes, London, England, have invent- 5 ed certain new and useful Improvements in Metallic-Filament Incandescent Electric Lamps, of which the fication.

The present invention relates to metallicfilament electric lamps with the illuminating body carried back and forth over the retainin parts of a supporting frame.

candescent electric lamps are already known, in which the illuminating body is placed zigzag upon the holders which are arranged in parallel planes upon a common supporting stem; in'these cases the illuminatmg body is carried over hooks provided at the supporting-ends of the holders.

This construction, however, has the disadvantage that the illuminating body ma be disengaged from the slender elastic hol ers commonly employed on the end of the supporting stem that is farthest away from the base, when very severe shocks occur in the direction of said supporting stem. The

above occurrence may be due to the fact that the elastic holders are weighted beyond their limit of elasticity, so that they be- 4 come permanently distorted.

It is a practice already known to proceed in the application of the illuminating body in such manner that the hook-like supporting parts, after the illuminating body is put in place, are bent so as to form a closed eye, whereby the danger of the illuminating -bodys slipping from the holders is almost obviated, but this process requires special manipulation after the filament is applied,

which manipulation under some circume stances may endanger the illuminating body.

The disadvantages above set forth are avoided by the resent invention which may be understood roin the following descrip- 5 tion taken in connection with the attached drawings, in which Figure 1 shows an embodiment of my invention in a complete lamp; Fig. 2 shows an enlarged view of a support; Fig. 3 shows a section through the coil near its contact with the filament, and Fig. 4: shows a modification in which the support is given a number of helical turns. reference to the drawings, it will be seen that the supporting ends of the practically rigid holders 1-1, which are near the base,

following is a speci-.

are made in the form of helical eyes 2, 2 and are turned toward the elastic holders 66 as shown in Figs. 1 and 2, while the elastic holders are provided with hooks 3, 3 in the ordinary .manner. The eyes 2--2 permit a more convenient and more secure location of the lighting body 4, and at the same time revent the lighting body from sliding ofl' t e rigid holders. Moreover, the movement of the sections of the lighting body, which is caused by an axial shock directed toward the base is limited not merely by one, but by two, points of support as shown at 2 and 5 in Fig. 3, so that the elastic holders are relieved with greater certainty. In order to represent this effect, a section through the eye is shown in Fig. 3, and the corresponding curve of the bight of the lighting body is represented not only in normal position, but it is also shown in dotted lines in the position which it assumes when it receives a blow. According to the modification shown in Fig. 4 the ends of the substantially rigid holders adjacent to the socket are provided with a number of helical turns 7-7, three being shown in this instance, and the illuminating body 4 is so arranged in one of the turns, say the middle one, that on both sides of the bight of the illuminatin body other turns are provided which a ford additional points of contact in case of axial shock and also increased security against the slipping off of the illuminating body from the holders. In this modification the coiled end of the supports is turned away from the flexible supports. By the use of the present invention, the filament can be applied rapidly and without drawing it through an eye, while at the same time, all the advantages of the closed eye are obtained. The same is true of the structure shown in the other figures.

What ll claim as new and desire to secure by Letters Patent of the United States, is

1. In an incandescent lamp, the combination of a central supporting stem, a plurality of sets or supports mounted thereon, the members of one set being flexible and having hooks on the ends thereof, the members of another set being comparatively rigid and having an open coil in the outer end thereof, a continuous refractory filament strung back and forth between the members of the sets or" supports so that the axial movement of the filament in the direction of the rigid supports is limited by the coiled portion in:

the'llgld support. 7 i

In an incandescent lamp, a central supporting stem, aplural'ity of hooked flexible supports mounted thereon, a plurality of rigid supports mounted thereon, said rigid supports having a helical coil on the end thereof, and a continuous filament strun back and forth between said supports and capable of longitudinal movement with respect to the rigid supports, the filament being arranged to engage the rigid support at one point under normal conditions and at a plurality of points under abnormal conditions.

.3. In an incandescent lam ,a central supporting stem, a hooked exible support mounted thereon, a rigid support mounted thereon, said rigid support having a helical coil on the end thereof, said coil consisting of more than one turn, a continuous filament strung back and forth between said flexible and rigid support, said filament normally engaging one spire of said coiled portion of the rigid support and engaging two ad acent spires of said coil on movement caused by abnormal conditions.

4. The combination in an incandescent} lamp of a filament support having a helical coil on the end thereof, said coil consisting of more than one turnand a filament normally.engaging one spire of said coiled portion under abnormal conditions.

In witness whereof, I have hereunto set my hand this 16th day of Sept, 1912.

EMIL GEISEL. I

Witnesses:

O. J. WIRTH, C. P. LmnoN.

and-engaging two adjacent spires- 

